fix(icons): icon-only button accessibility pass

Swept every icon-only button app-wide for an accessible name. Found
three relying on title-only (not reliably announced by screen
readers) or nothing at all: region-selector's detect-location button,
the carousel add-to-cart button, and the subcategories add-to-cart
button (had no label at all). All now have aria-label.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/components/items-carousel/items-carousel.component.html

@@ -51,7 +51,7 @@
                                         <span class="current-price">{{ product.price }} {{ product.currency }}</span>
                                     }
                                 </div>
-                                <button class="cart-icon-btn" (click)="addToCart($event, product)" [title]="'carousel.addToCart' | translate">
+                                <button class="cart-icon-btn" (click)="addToCart($event, product)" [attr.aria-label]="'carousel.addToCart' | translate">
                                     <app-icon name="cart" [size]="16" />
                                 </button>
                             </div>

src/app/components/region-selector/region-selector.component.html

@@ -18,7 +18,7 @@
       <div class="dropdown-header">
         <span>{{ 'location.chooseRegion' | translate }}</span>
         @if (!detecting()) {
-          <button class="detect-btn" (click)="detectLocation()" title="{{ 'location.detectAuto' | translate }}">
+          <button class="detect-btn" (click)="detectLocation()" [attr.aria-label]="'location.detectAuto' | translate">
             <app-icon name="locate" [size]="14" />
           </button>
         }

src/app/pages/category/subcategories.component.html

@@ -78,7 +78,7 @@
                     <span class="current-price">{{ item.price }} {{ item.currency }}</span>
                   }
                 </div>
-                <button class="item-cart-btn" (click)="addToCart(item.itemID, $event)">
+                <button class="item-cart-btn" (click)="addToCart(item.itemID, $event)" [attr.aria-label]="'carousel.addToCart' | translate">
                   <app-icon name="cart" [size]="16" />
                 </button>
               </div>